Hundreds of meters below the surface of the freezing ocean surrounding Antarctica, the seafloor is teeming with life. The animals living there have no idea that an army is on the brink of invading their tranquil environment.

In some regions of the Arctic, polar bears will spend their entire lives on sea ice or the ocean.
Christopher Michel/flickrJuly 17, 2015

The peppered moth will always hold a special place in the annals of evolutionary biology. Its story is a classic example of natural selection, and of how animals can act as indicators of environmental change.

The tropical orange blotch surgeon fish has been moving south into New South Wales.
Graham Edgar / Reef Life SurveyJuly 14, 2015